Extractive membrane bioreactor (EMBR): Recent advances and applications

[Display omitted] •EMBR provides the possibility of removing specific pollutants from a wastewater.•Biomass and waste are kept separated for improving both streams optimization.•Membrane helps to protect microorganism from direct contact with toxic species.•More works are needed to develop highly selective and permeable membrane.•Biofilm thickness optimization and control need more exploration. Combining bioreactor and membrane, known as a membrane bioreactor (MBR), has been considered as an attractive strategy to solve the limitations of conventional activated sludge process, such as biological instability, poor sludge quality, and low concentration of mixed liquor suspended solid. Unlike the other MBRs, extractive membrane bioreactor (EMBR) focuses on enhancing the efficiency of wastewater treatment through toxic compounds extraction by using a selective membrane. Even though EMBR has been successfully demonstrated in wastewater and waste gas treatment by several studies, it still faces some obstacles such as biofilm formation and low selectivity of the membrane towards a specific component. Appropriate biofilm formation control strategies and membrane with high selectivity are needed to solve those problems. This paper reviews EMBR including its potential applications in wastewater treatment, denitrification process, and waste gas treatment. In addition, challenges and outlook of EMBR are discussed.